1999/08/31 by S. Moukouri, S. Allen, Frédéric Lemay +8 · 3 citations
Physics and Astronomy · #Advanced Condensed Matter Physics #Physics of Superconductivity and Magnetism #Quantum and electron transport phenomena #cond-mat.str-el #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.61.7887
published as Phys. Rev. B 61, 7887-7892 (2000). · Accepted, Phys. Rev. B15 15Mar00. Expanded version of original submission, Latex, 8 pages, epsfig, 5 eps figures (Last one new). Discussion on fluctuation and strong coupling induced pseudogaps expanded
arxiv created 2000/01/05 · openalex publication_date 2000/03/15 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/30
The opening of a critical-fluctuation-induced pseudogap (or precursor pseudogap) in the one-particle spectral weight of the half-filled two-dimensional Hubbard model is discussed. This pseudogap, appearing in our Monte Carlo simulations, may be obtained from many-body techniques that use Green functions and vertex corrections that are at the same level of approximation. Self-consistent theories of the Eliashberg type (such as the fluctuation exchange approximation) use renormalized Green functions and bare vertices in a context where there is no Migdal theorem. They do not find the pseudogap, in quantitative and qualitative disagreement with simulations, suggesting these methods are inadequate for this problem. Differences between precursor pseudogaps and strong-coupling pseudogaps are also discussed.